*{
    padding: 0;
    margin: 0;
    list-style-type: none;
}
#mainBox{
    padding: 20px;
    width: 800px;
    margin: 5px auto;
    border-radius: 20px;
    border: 2px solid skyblue;
    background-color: rgb(243, 243, 243);
    box-shadow: 1px 1px 5px gray;
}
#mainBox>h2{
    display: block;
    text-align: center;
    margin-top: 20px;
    margin-bottom: 20px;
}
#classesBox{
    width: 100%;
}
#classesBox>ul{
    display: flex;
    margin: 20px 0;
    border: 1px solid black;
    border-radius: 10px;
    box-shadow: 2px 2px 10px black;
}
#classesBox>ul>li{
    font-size: 14px;
    color: rgb(95, 95, 95);
    flex: 1;
    text-indent: 1em;
    height: 50px;
    line-height: 50px;
}